CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Statement of Comprehensive Income [Abstract]
Income taxes, unrealized holding gain (loss) on derivatives	$ 221	$ (839)	$ 74	$ (1,123)
Income taxes, reclassification for loss (gain) on derivatives included in net earnings	(28)	391	(77)	417
Income taxes, net unrealized loss on derivatives	193	(448)	(3)	(706)
Income taxes, net gain of defined benefit obligation	0	0	0	4
Income taxes, amortization of prior services of defined benefit obligation	0	(2)	(1)	(1)
Income taxes, defined benefit obligation	$ 0	$ (2)	$ (1)	$ 3